A dark patch of hydrocarbon haze, wider than Earth, develops and swirls in a new movie clip from ultraviolet images taken by NASA's Cassini spacecraft of Jupiter's upper atmosphere, or stratosphere.

Observations in the ultraviolet part of the light spectrum reveal features in Jupiter's stratosphere that are transparent in the visible-light portion of the spectrum. One surprise is the dark vortex whose birth and migration can be seen during the 11-week span of the movie taken while Cassini was approaching Jupiter in late 2000. Development of this feature resembles development of ozone holes in Earth's stratosphere in that both processes appear to occur only within confined masses of high-altitude polar air. The similarity may help scientists understand both processes better.

The movie clip and a still image mapping all 360 degrees of Jupiter in ultraviolet are available online from NASA's Jet Propulsion Laboratory, Pasadena, Calif., at

A video file related to this release will air on NASA Television March 13 and 14 during the NASA TV video file feed scheduled for noon, 3 p.m., 6 p.m., 9 p.m., and midnight EST. NASA TV is broadcast on GE-2, transponder 9C, C-Band, located at 85 degrees West longitude. The frequency is 3880.0 MHz. Polarization is vertical and audio is monaural at 6.8 MHz. For general questions about NASA video files, contact Fred Brown, NASA TV, Washington, D.C. (202) 358-0713.

Cassini made its closest pass to Jupiter on Dec. 30, 2000, gaining a gravitational boost for reaching its main destination, Saturn, in 2004. More information about the mission is available at http://saturn.jpl.nasa.gov . Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the Cassini and Galileo missions for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena.